http://media.gm.com/division/2005_prodinfo/powertrain/engines/05_car_engine_specs.html#ls4

Looking at the Graphs for 3 motors (the LS4 5.3L V8, the Northstar 4.6 and the ‘old’ L67) I find the following of interest:

= = = = = = 5.3L . . . . 4.6 . . . . L67

HP @ 2000 . 115 . . . . 100 . . . . 100
TQ @ 2000 . 300 . . . . 265 . . . . 250

HP @ 3000 . 180 . . . . 150 . . . . 160
TQ @ 3000 . 310 . . . . 275 . . . . 270

HP @ 4000 . 245 . . . . 225 . . . . 220
TQ @ 4000 . 320 . . . . 295 . . . . 280 (past peak)


[these numbers are approximate, from these dyno curves - trying to line this data up as a chart . . .]

Point being, compared to the L67 (a known and appreciated torque generator) and the Northstar (I have driven the new STS with this version of the motor – it is technically sophisticated, expensive to produce and I certainly respect it), this new 5.3L V8 quoted output is quite impressive. At least on paper.

I end up spending a LOT of my drive time with the motor turning between 2000 and 4000 rpm. The torque available in this range is more important to me (most of the time) than peak horsepower.

The 5.3L LS4 generates more torque and more horsepower at every point from 2000 to 4000 rpm than either of these other motors.

I am looking forward to driving this car.

- Ray
Admitted torque addict . . .